Biomedical subjects

M Wedel

Publications and source records attributed to M Wedel.

At least 37 records · Page 2Linked to original sources

PubMed1990

Nutrition and aging: nutritional status of "apparently healthy" elderly (Dutch nutrition surveillance system).

In a nationwide survey the nutritional status was assessed of 539 apparently healthy, independently living elderly aged 65-79 years. Anthropometric data showed no energy deficits. The prevalence of anemia was 4 and 1% among men and women, respectively. Many elderly showed a low level of 25-hydroxyvitamin D in plasma (less than 31 nmol/L: men 35%; women 43%), indicating a marginal status. Although the prevalence of low blood levels of folate, pyridoxal-5'-phosphate, and total carotenoids was higher among the elderly than among younger adults, clear (clinical) signs of nutritional deficiencies were not observed. Prevalence of obesity (13%), hypercholesterolemia (38%), and hypertension (63%) was found to be high, the percentages being higher for women than for men. Several indicators of the nutritional status appeared to differ among age groups. It is concluded that few differences can be considered as being due to physiological aging, which finding should be reflected in reference values for elderly people.

Age Factors↗

PubMed1990

Effect of dietary fiber on the vitamin B6 status among vegetarian and nonvegetarian elderly (Dutch nutrition surveillance system).

To obtain more insight into the effect of dietary fiber on vitamin B6 status among elderly people, we studied dietary interrelationships as well as associations between dietary intake and plasma pyridoxal-5'-phosphate (PLP) and cofactor stimulation of aspartate aminotransferase in erythrocytes (EAST-AC) among 441 nonvegetarian (aged 65-79) and 32 vegetarian elderly (aged 65-94). EAST-AC was found to be inversely related with intake of vitamin B6 and dietary fiber in bivariate regression analyses. After adjustment for age, intake of energy, protein, and fiber, the intake of vitamin B6 was still inversely related with EAST-AC. The association between EAST-AC and dietary fiber disappeared in the multivariate analysis, whereas total protein intake proved to be positively related with EAST-AC in the multivariate analysis only. The differences between bi- and multivariate analyses are most likely due to the observed interrelationships between intake of vitamin B6, fiber, and protein. It is concluded that dietary fiber does not have a significant impact on the vitamin B6 status among Dutch elderly people, since only protein (positively) and vitamin B6 (inversely) intake appeared to be related with EAST-AC in the multivariate analysis.

Aged↗

PubMed1990

Long-term effects of a vegetarian diet on the nutritional status of elderly people (Dutch Nutrition Surveillance System).

The health and nutritional status (anthropometry, and blood and urine biochemistry) of 44 Dutch apparently healthy vegetarians, aged 65-97 years, refraining from meat, fish, and poultry consumption, was assessed for insight into long-term consequences of ovo-lacto- or lacto-vegetarianism. The results indicate that in comparison to omnivorous elderly the vegetarian elderly (especially men) have aged successfully with respect to cardiovascular risk factors. In contrast, vegetarian elderly are at a higher risk for a marginal iron, zinc, and vitamin B12 status. Although several vegetarian elderly showed low levels of 25-hydroxyvitamin D in plasma and many had low values of 24-hr urine volume (per kg body weight), these values are not likely the result of a vegetarian diet per se. It is concluded that, although some nutrition-related risks are prevalent among vegetarian elderly, these risks can probably be prevented by lifestyle changes.

25-Hydroxyvitamin D 2↗

PubMed1990

Vitamin A intervention: short-term effects of a single, oral, massive dose on iron metabolism.

A group of 134 school children aged 3-9 y, with signs of conjunctival xerosis, from the rural area of the Sakorn Nakhon province in Northeast Thailand were selected for a controlled study on the short-term effect (2 wk) of a single, oral high dose of vitamin A on iron metabolism. After collection of the baseline data, children within villages were randomly assigned to receive the capsules (n = 65) or serve as control subjects (n = 69). Two weeks after supplementation significant increases of retinol, retinol-binding protein, hemoglobin, hematocrit, serum iron, and saturation of transferrin were found in the supplemented group. Ferritin concentrations did not change significantly. These short-term changes completely exclude seasonal effects and change in morbidity. This study provides further evidence of a causal association between vitamin A and iron metabolism. In areas where vitamin A deficiency is endemic, periodic massive vitamin A dose programs can also improve iron status of the population.

Administration, Oral↗

PubMed1990

Dependence of vitamin B-6 status assessment on alcohol intake among elderly men and women (Dutch Nutrition Surveillance System).

To obtain more insight into the effect of moderate alcohol intake on vitamin B-6 status indicators, we studied the associations of alcohol intake (unadjusted and adjusted for intake of vitamin B-6 and protein) with the erythrocyte aspartate aminotransferase activation coefficient (EAST-AC) and plasma pyridoxal 5'-phosphate (PLP) level. Data obtained from men (n = 224) and women (n = 217) aged 65-79 (nationwide sample in the Netherlands) were used for this purpose. Although alcohol intake (a maximum of 21% of the energy came from alcohol) tended to be positively associated with PLP, this association never reached statistical significance (p greater than or equal to 0.05). EAST-AC was inversely associated with alcohol intake, whether or not it was adjusted for vitamin B-6 and protein intake. Similar results were found for the total EAST activity (after adding PLP) or apoenzyme activity; the basal EAST activity (before adding PLP) or holoenzyme activity was not associated with the alcohol intake. These results indicate that caution is needed in the interpretation of the specificity of EAST-AC (i.e., the degree to which EAST-AC is unaffected by other factors) as an indicator of vitamin B-6 intake.

Aged↗

PubMed1990

Mild vitamin A deficiency and risk of respiratory tract diseases and diarrhea in preschool and school children in northeastern Thailand.

A cross-sectional study, a follow-up study, and an intervention trial were carried out to investigate the association between mild vitamin A deficiency and the occurrence of diarrhea and respiratory diseases. Cross-sectional analysis was performed among 1,772 children, aged 1-8 years, in the Sakon Nakhon province of northeastern Thailand. Children with a history of diarrhea or respiratory disease had lower levels of serum retinol and retinol-binding protein. Adjusted for age, sex, nutritional status, and level of urbanization, logistic regression using data for 877 children showed a negative association between serum retinol and both diarrhea and respiratory diseases. A follow-up three months later (n = 146 children) showed that children with deficient serum retinol (less than 0.35 mumol/liter) had a fourfold greater risk of respiratory disease (p less than 0.01). No relation was found for diarrhea. An intervention trial (n = 166 children aged 1-5 years) showed that, during 2 months of follow-up after administration of oral vitamin A (200,000 IU), the control group (aged 3-5 years) had a higher incidence of respiratory disease (2.9 times) as well as diarrhea (3.1 times). Between 2 and 4 months, a significantly (p less than 0.025) higher incidence of respiratory diseases (2.5 times) could be observed in children aged 1-2 years. This study supports earlier reports on a greater risk of respiratory diseases and of diarrhea in mild vitamin A deficiency. Supplementation reduced the incidence of both diarrhea and respiratory disease for a period of at least 2 months.

Administration, Oral↗

PubMed1990

Single intrauterine fetal death in a suspected monozygotic twin pregnancy.

The antepartum death of a fetus in a twin pregnancy is associated with significant risk of mortality and morbidity in the surviving infant. A recent case of single intrauterine death in a suspected monozygotic twin pregnancy at a regional hospital prompted a study of similar cases in the hospital's recent experience and a review of the current literature. We report the successful conservative management of fetal death in a monozygotic twin pregnancy.

Adolescent↗

PubMed1990

Association between intestinal parasitoses and nutritional status in 3-8-year-old children in northeast Thailand.

To assess the prevalence and species of intestinal parasitoses and to evaluate the effects of parasitic infections on the nutritional health of northeastern Thai children a survey was carried out among 343 urban and rural 3-8-year-olds in Sakon Nakhon province. Approximately 57% suffered from single or multiple helminthiasis (ancylostomiasis (AD), ascariasis (AL), opisthorchiasis (OV) and/or strongyloidiasis (SS)) and/or giardiasis (GL). In rural areas the prevalence of AD and SS was higher than in urban areas (p less than 0.01 and p less than 0.05 respectively). OV was found more frequently among 6-8-year olds (18%) than among 3-5-year olds (5%); among 3-5-year olds the prevalence of GL was higher than among 6-8-year olds (17 vs 8%). Multiple infections were observed in 13% of the children. Infected children showed lower daily intakes of protein, iron and riboflavin as well as lower menas for haemoglobin, haematocrit, serum ferritin, and Z-score height for age than non-infected children. The prevalence of stunted children was lower among non-infected children (32%) than among infected children (53%), and children with AL (49%), SS (55%), and GL (45%). Anaemia was found more frequently among the infected children (59%) and GL-children (61%) than among non-infected children (42%). Inadequate daily intake of energy and nutrients of most of the children, in combination with parasitic infections, still common in rural northeast Thailand, was shown to result in a serious public health problem.

Child↗

PubMed1990

Effects of a moderate dose of alcohol on blood lipids and lipoproteins postprandially and in the fasting state.

Effects of a moderate dose of alcohol on blood lipids and lipoproteins were studied in volunteers of two age groups (20-30 and 45-55 years), each consisting of eight healthy men. The alcohol (30 g in red port and wine) was consumed during a standard dinner. Two blood samples were drawn: one in the postprandial phase, and one the next morning after fasting overnight. In the postprandial phase, one hour after intake, alcohol increased high-density lipoprotein cholesterol (HDL-C) by 11.5%, triglycerides (TG) by 15.3% and apolipoprotein A2 (Apo-A2) by 7.3% (P = 0.002, P = 0.044 and P = 0.024, respectively). The increase in HDL-C appeared to be mainly attributed to the HDL2-C subfraction which increased by 15.3% (P = 0.066). Furthermore, the increases in HDL-C, HDL2-C and TG were more pronounced in the middle-aged men then in the young men. After fasting overnight the effects of alcohol had disappeared.

Adult↗

PubMed1990

Parameter estimation in a three-compartment model for blood alcohol curves.

Models of alcohol input and absorption are crucial to the description and understanding of the effects of alcohol in the human body. In this paper, the pharmacokinetics of alcohol after oral administration are described by a three-compartment model with a supposed concentration-dependent absorption and elimination. The absorption of alcohol from the small intestine into the blood is represented by a first-order rate constant ka. To describe the delay in peak concentration of alcohol the gastric emptying rate is represented as a first-order parameter with a feedback control depending on the amount of alcohol remaining in the stomach. The alcohol ingestion can then be represented as a bolus input. The elimination process is described by a model similar to the Michaelis-Menten model for enzyme kinetics. Parameters are estimated by means of an iterative algorithm minimizing a non-linear function. A good fit of the model was obtained for blood alcohol curves from six men and six women who each had received an alcohol dose of 28.5 g on three consecutive days. It is concluded that the model can be recommended to describe adequately the absorption and elimination of alcohol.

Adult↗

PubMed1990

Vitamin D status, parathyroid hormone and sunlight in Turkish, Moroccan and Caucasian children in The Netherlands.

At the end of the winter circulating concentrations of 25-hydroxyvitamin D (25-OHD) in Asian and Mediterranean immigrants in northwestern European countries are usually very low. This may lead to vitamin D deficiency and eventually to rickets. Children are more prone to develop vitamin D deficiency. The vitamin D status of 8-year-old Turkish, Moroccan and Caucasian children was assessed by measuring plasma concentrations of 25-OHD and parathyroid hormone (PTH) and related to the cumulated global sun radiation (CGSR). The study population was selected from school children in The Hague and Rotterdam (The Netherlands). In each city blood samples were examined from 40 migrant children and a Caucasian reference group (n = 40) (matched for age and sex). Children in The Hague were examined at the end of the winter and early spring (February/April) and those in Rotterdam in late spring and early summer (May/June). Mean plasma 25-OHD concentrations for the migrant children in both cities were significantly lower than for the Caucasian reference group. The lowest 25-OHD values were measured in migrant children in The Hague: 42 per cent of the Turkish and 23 per cent of the Moroccan children had plasma levels less than 20 nmol/l. In these groups hyperparathyroidism (PTH greater than 85 pmol/l) was significantly more prevalent. With all pooled data a significant correlation between plasma 25-OHD and PTH was observed (r = -0.24; P less than 0.001). Regression analysis indicated that the relationship between both variables did not differ among the three ethnic groups. As expected, 25-OHD concentrations were higher for increased CGSR. Differences in 25-OHD level are mainly explained by differences in skin pigmentation and calcium intake between Mediterranean and Caucasian children. The secondary hyperparathyroidism observed in some children confirms that migrant children have a higher risk of developing nutritional rickets when living in areas with a moderate climate.

Child↗

PubMed1989

Iron metabolism and vitamin A deficiency in children in northeast Thailand.

To investigate the association between vitamin A and iron metabolism, two studies were carried out: a cross-sectional study and an intervention trial. The cross-sectional analysis was carried out in 1060 children aged 1-8 y. Multiple-regression analysis was used to adjust for effects of age, gender, indices of the protein nutritional status, and infections. Retinol was significantly associated with hematocrit, serum Fe, transferrin, ferritin, and saturation of transferrin (%ST). To obtain further evidence as to whether this observed association is a causal one, an intervention trial was carried out. After collection of the baseline data of 300 children, 166 children with a hemoglobin concentration less than 7.5 mmol/L were selected. A random sub-sample of 78 children received vitamin A capsules; the other children served as control subjects. Two months after supplementation significant differences, adjusted for age, were found for retinol, retinol-binding protein, serum Fe, and %ST between the supplemented and the control group. After 4 mo none of the indices were found to be significantly different between the supplemented and the control group. Periodic massive doses of vitamin A may play a role in improving the Fe status as well.

Blood Chemical Analysis↗

PubMed1989

Dose-response relationships regarding vitamin B-6 in elderly people: a nationwide nutritional survey (Dutch Nutritional Surveillance System).

The dietary intake and biochemical status of vitamin B-6 in 476 apparently healthy Dutch elderly people (aged 65-79 y), who were not using drugs known to affect vitamin B-6 metabolism, were evaluated. Intake of vitamin B-6 per gram protein was related to biochemical data, namely plasma pyridoxal 5'-phosphate (PLP) and cofactor stimulation of aspartate aminotransferase in erythrocytes (AST-AC). Based on a cutoff point of 2.02 for AST-AC, approximately 9% of the elderly people not using vitamin B-6 supplements had a marginal vitamin B-6 status. About 7% were using vitamin B-6 supplements. Dietary intake of vitamin B-6 per gram protein was negatively related to AST-AC. Vitamin B-6 intakes per gram protein higher than 0.020 mg were necessary to ensure an AST-AC value less than 2.02. At high PLP values AST-AC hardly varied. The results seem to indicate a higher requirement of vitamin B-6 in elderly people than in younger adults.

Aged↗

PubMed1989

A prevalence study of vitamin A deficiency and xerophthalmia in northeastern Thailand.

An epidemiologic survey of the prevalence of xerophthalmia and vitamin A deficiency was conducted in May and June 1985 in a multistage random sample of 1,772 children 1-8 years of age from 16 rural villages and the capital city of the Sakon Nakhon province in northeastern Thailand. Data of clinical eye examinations were available for 92% (n = 903) of the eligible children aged 1-5 years (n = 982); history of night blindness was obtained from a reliable source from 93% (n = 1,644) of the whole sample; and biochemical data were available for 60% (1,060) of the children examined. The distribution of clinical signs of xerophthalmia and serum retinol levels differed between the rural and urban areas. In the urban area, no signs of xerophthalmia or deficient serum retinol levels were found in the preschool children examined. The prevalence of night blindness in the rural area was 1.3% in children aged 1-5 years (95% confidence interval (Cl) 0.7-1.9); Bitot's spots were seen in 0.4% (95% Cl 0.1-1.0); 12.7% (95% Cl 9.9-15.5) showed deficient serum retinol levels (less than 0.35 mumol/liter). Of the children aged 1-8 years, 9.6% (95% Cl 7.8-11.4) showed deficient serum retinol levels. In the rural area, the prevalence of night blindness, Bitot's spots, and deficient serum retinol levels indicates a problem of public health importance according to World Health Organization criteria.

Child↗

PubMed1989

Fat patterning during weight reduction: a multimode investigation.

Changes in body composition during weight reduction of 20 obese women were quantified by anthropometry (weight, waist and hip circumferences, skinfold thicknesses determined with a skinfold caliper and ultrasonically), densitometry (hydrostatic weighing), tetrapolar bioelectrical impedance (TBI) and computed tomography (CT scan of abdomen and thorax). The average reduction in mean weight (92.7 kg), induced by an energy restricted diet over a period of 12 wk was 5.6 kg (5.8%). Fat areas were calculated from the CT scans of the thorax; intra-abdominal fat and subcutaneous fat were separately calculated from the abdominal CT scans. Anthropometric and CT fat values were found to decrease significantly during weight reduction, whereas the percentages of body fat as determined by densitometry and TBI did not. The relative deposition of intra-abdominal and subcutaneous fat of 19 women did not essentially change after weight reduction. One woman, who had a relatively large intra-abdominal fat accumulation, lost more subcutaneous fat than intra-abdominal fat. It is concluded that in general fat patterning does not change during weight reduction.

Adipose Tissue↗

PubMed1988

The reproducibility of the conversion of nitrate to nitrite in human saliva after a nitrate load.

We investigated the reproducibility of the inter- and intra-individual variations in the conversion of nitrate to nitrite in saliva. Saliva samples were collected from 20 volunteers just before and at regular intervals after a nitrate load on four non-consecutive days within a period of 2 months. On three occasions beetroot juice was the nitrate source and on one occasion a nitrate solution was given. Despite large day-to-day variations it was possible to discriminate between subjects with a consistently high or low nitrate conversion after a nitrate load. Neither saliva sampling before a nitrate load nor single saliva samples are sufficient to obtain clear information about individual capacities for nitrate-nitrite conversion.

Ascorbic Acid↗

PubMed1988

Thiamin, riboflavin, and vitamins B-6 and C: impact of combined restricted intake on functional performance in man.

A double-blind study of combined restriction of thiamin, riboflavin, and vitamins B-6 and C was carried out with 23 healthy males. During 8 wk of low vitamin intake, 12 deficient subjects consumed daily a diet of normal food products, providing maximally 32.5% of the Dutch Recommended Dietary Allowances (RDA) for thiamin, riboflavin, vitamins B-6 and C. Other vitamins were supplemented at twice the RDA. Eleven control subjects consumed the same diet but with a supplementation of twice the RDA of all vitamins. In deficient subjects blood vitamin levels, urinary vitamin excretion, and erythrocytic enzyme activities decreased; in vitro enzyme stimulation increased. Vitamin depletion had no ill effects on health, physical activity, and mental performance. A significant decrease was observed in aerobic power (VO2max) and onset of blood lactate accumulation (p less than 0.001) of 9.8 and 19.6%, respectively. A combined restricted intake of thiamin, riboflavin, and vitamins B-6 and C causes a decrease in physical performance within a few weeks.

Adult↗

PubMed1988

Influence of several factors on blood alcohol concentrations after drinking alcohol.

The influence of several factors on the blood alcohol course after drinking diluted ethanol was studied in young, healthy volunteers under strictly standardized conditions. These factors were sex, dose and concentration of the alcohol, physical exercise immediately after drinking, meal consumption before drinking and energy content and composition of the meal. In 18 blood samples, taken within 6 hr after alcohol ingestion, blood alcohol concentration (BAC) was determined enzymatically. Concomitantly breath analyses were performed. In general, both methods gave similar results. Peak concentration and area under the blood alcohol curve increased with increasing dose. With the same amount of ethanol, peak concentration and area under the curve tended to be greater in women than in men. Consumption of a meal had an attenuating effect. The area under the curve was smaller after a high-energy meal than after a low-energy meal. Peak concentration depended on meal composition, increasing in the order high protein less than high sucrose = high complex carbohydrate less than high fat. A similar trend was observed for the area under the blood alcohol curve.

Adult↗